1. Field of the Invention
The present general inventive concept relates to a method to transmit data more effectively, and more particularly, to a method to transmit data to a group comprising a plurality of reception stations that receive the same data from a transmission station when the stations transmit and receive the data in a power line communication (PLC) network.
2. Description of the Related Art
A power line communication (PLC) network technology is used to build a communication network for a home network. The PLC network technology uses existing power lines in houses. Accordingly, unlike Ethernet networks, PLC networks do not need additional wiring work, and can be used in basements or shaded areas that wireless networks cannot reach.
Conventionally, stations in a PLC network communicate using two communication methods. One such communication method is a unicast method that is a one-to-one communication method between stations using channel estimation and its result, and a tone map. Another communication method is a broadcast method that transmits data from a transmission station to the PLC network using all channels, without dividing the channels into sub-channels. The stations communicate data using the unicast method, and management information or control information using the broadcast method.
FIG. 1A is a layout diagram illustrating a unicast method that is a one-to-one communication method between stations. Referring to FIG. 1A, a transmission station transmits a data frame to reception stations 3 through 5. The transmission station and each of the reception stations communicate data one-to-one. Therefore, a transmission sub-channel selected by estimating a channel between the transmission station and the station 3 is different from a transmission sub-channel selected by estimating a channel between the transmission station and the station 4. Other stations 2 and 6 that do not communicate data with the transmission station can exist in a PLC cell.
FIG. 1B is a layout diagram of a broadcast method that transmits data to all reception stations 2 through 6 included in a PLC cell from a transmission station. Referring to FIG. 1B, the transmission station transmits data to all the reception stations 2 through 6 included in the PLC cell. Therefore, when the transmission station attempts to transmit data to the reception stations 3 through 5, the reception stations 2 and 6 receive the same data as those received by the reception stations 3 through 5.
According to the unicast method, when the transmission station transmits the same data to the plurality of reception stations, the same data frame must be repeatedly transmitted, causing waste of a channel bandwidth. According to the broadcast method, since a data frame must be transmitted to all the reception stations included in the PLC cell, data is transmitted to a reception station that is not supposed to receive the data.
Therefore, even when the same data is transmitted to the plurality of reception stations in the PLC network, it is necessary to prevent the waste of the channel bandwidth due to the repetitive transmission of the data frame, and it is also necessary to prevent the transmission of the data frame to a reception station that is not supposed to receive data.